Add cinnamon sticks (these are cheapest in bulk at Winco), whole cloves, and whole allspice (which I was out of, so it's not in the picture)
Bundle it up and tie it with twine.
Slice up oranges, lemons, and/or apples. It's a good way to use fruit that has gotten too ugly to eat. If your kids like their apples peeled, you could throw in the peels. I was out of lemons, but it also smells great with apples and oranges. Just add about 4 cups of water to the pan and simmer.
You can add more water and re-boil for about 2-3 days. After that it gets gross and you'll need to start over fresh. It is a lot easier to throw away the bundle of spices, than have them floating all over the pan!